Field
Aspects of the present invention generally relate to an image forming apparatus equipped with a sensor, and also relates to a method for controlling the image forming apparatus.
Description of the Related Art
With increasing social awareness concerning environmental issues, many image forming apparatuses (e.g., copying machines) are configured to automatically shift into a power saving state, e.g., where supplying electric power to a printer unit and a scanner unit is stopped to reduce electric power consumption in a standby state, if they are not operated for a predetermined time.
When a user starts operating an image forming apparatus having shifted into the power saving state, it is necessary for the user to press a button to cause the image forming apparatus to return from the power saving state. Further, the user typically needs to remain in front of the image forming apparatus for a period of time after pressing the button because a significant time lag can occur before the image forming apparatus becomes available. In view of the foregoing, an image forming apparatus can be configured to return from the power saving state automatically when a human body is detected by a human body detection sensor.
For example, as discussed in Japanese Patent Application Laid-Open No. 2012-177796, an image forming apparatus is configured to include two sensors that are different in characteristics. According to the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-177796, a second sensor is delayed in turn-on timing compared to a first sensor. More specifically, the second sensor turns on if a human body enters a detection range of the first sensor. Further, the second sensor is narrower in detection range compared to the first sensor. The image forming apparatus returns from the power saving state if the human body enters the detection range of the second sensor.
However, the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-177796 may cause error detections depending on usage environment thereof. For example, in a case where the image forming apparatus is placed in one corner of a room, most of the persons approaching the image forming apparatus intend to operate the image forming apparatus. However, in a case where an image forming apparatus is placed in a passageway, persons passing in the vicinity of the image forming apparatus can either intend to use the image forming apparatus or can merely be passing by the image forming apparatus. According to the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-177796, the detection range of the second sensor is set to be approximately 0.5 meters (m) to prevent the image forming apparatus from erroneously returning from the power saving state in response to a merely passing by the image forming apparatus.
If the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-177796 is installed in the above-described corner of the room, the image forming apparatus does not return from the power saving state unless each person enters the detection range (0.5 m) of the second sensor even though most of the persons passing in front of the image forming apparatus intend to use the image forming apparatus. If the detection range of the second sensor is widened to provide a wider user detection range, the image forming apparatus may erroneously return when a person merely passes in front of the image forming apparatus in the case where the image forming apparatus is placed in a passageway.
If the image forming apparatus is installed at one corner of a room, users may want to widen the detection range of the human body detection sensor so that the image forming apparatus quickly returns from the power saving state when each user reaches a forward area of the image forming apparatus. Further, if the installation site of the image forming apparatus is a passageway, there will be users who wants to narrow the detection range of the human body detection sensor so that the image forming apparatus is prevented from erroneously returning from the power saving state when a person merely passes in front of the image forming apparatus. More specifically, considering various usage environments of the image forming apparatus, there is a need to appropriately change the sensitivity of the human body detection sensor with reference to usage environment thereof according to a user request.